Not that we would literally do this with Voyager, but it makes me wonder at the potential utility of a string of probes, one sent every couple of [insert correct time interval, decades, centuries?], to effectively create a communication relay stretching out into deep space somewhere.
My understanding with the Voyagers 1 and 2 is (a) they will run out of power before they would ever get far enough to benefit from a relay and (b) they benefited from gravity slingshots due to planetary alignments that happen only once every 175 years.
So building on the Voyager probes is a no-go. But probes sent toward Alpha Centauri that relay signals? Toward the center of the Milky Way? Toward Andromeda? Yes it would take time scales far beyond human lifetimes to build out anything useful, and even at the "closest" scales it's a multi year round trip for information but I think Voyager, among other things, was meant to test our imaginations, our sense of possible and one thing they seem to naturally imply is the possibility of long distance probe relays.
Edit: As others rightly note, the probes would have to communicate with lasers, not with the 1970s radio engineering that powered Voyagers 1 and 2.
What you are describing has been proposed before, for example within context of projects like Breakthrough Starshot. In that the case the idea is to launch thousands of probes, each weighing only a few grams or less, and accelerating them to an appreciable fraction of the speed of light using solar sails and (powerful) earth-based lasers. The probes could reach alpha centauri within 20-30 years. There seems to be some debate though about whether cross-links between probes to enable relaying signals is ever practical from a power and mass perspective vs a single very large receiver on earth.
Indeed. I think the main reason to send thousands of probes is increasing the odds that they will survive the trip and also be in the right position to gather usable data to transmit back.
Also once you have created the infrastructure of hundreds or thousands of very powerful lasers to accelerate the tiny probes to incredibel speeds, sending many probes instead of a few doesn't add much to the cost anyway.
No one likes to think this but it’s very possible voyager is the farthest humanity will go. In fact realistically speaking it is the far more likeliest possibility.
Provided we don't wipe ourselves out, there's no technical reason why we can't go interstellar. It's just way harder and more energy intensive than most people imagine, so I doubt it's happening any time in the next few hundred years.
But we already understand the physics and feasibility of "slow" (single-digit fractions of c) interstellar propulsion systems. Nuclear pulse propulsion and fission fragment rockets require no new physics or exotic engineering leaps and could propel a probe to the stars, if one was so inclined. Fusion rockets would do a bit better, although we'd have to crack the fusion problem first. These sorts of things are well out of today's technology, but it's not unforeseeable in a few centuries. You could likewise imagine a generation ship a few centuries after that powered by similar technology.
The prerequisite for interstellar exploration is a substantial exploitation of our solar system's resources: terraform Mars, strip mine the asteroid belt, build giant space habitats like O'Neill cylinders. But if we ever get to that point - and I think it's reasonable to think we will, given enough time - an interstellar mission becomes the logical next step.
Will we ever get to the point where traveling between the stars is commonplace? No, I doubt it. But we may get to the point where once-in-a-century colonization missions are possible, and if that starts, there's no limit to humanity colonizing the Milky Way given a few million years.
The other thing we could do to explore the galaxy is to become biologically something we would no longer recognize. We're viewing this from the lens of "humanity must remain biologically static" but I want to point out that that's not physically necessary here and that there is life on Earth that can stop its metabolism for decades and things like that.
Yes, it's incredibly easy to do these things once you've done all these other, incredibly difficult things first.
The furthest a human has been is 250k miles (far side of the moon). The fastest a human has traveled is only 0.0037% the speed of light.
The ISS is about 260 miles from the Earth. At that height, the gravity is actually roughly the same as on the surface, it's only because it is in constant freefall that you experience weightlessness on it.
Mars is 140 million miles away. And not exactly hospitable.
I like how you treat "the fusion problem" with a throwaway, "Yeah, we'd have to solve that" as if we just haven't sufficiently applied ourselves yet.
All of those incredibly difficult things we have not even begun to do are the technical reasons we have not gone interstellar and may be the reason we will never do so.
And even if we solve the issue of accelerating a human being to acceptable speeds to reach another star, the next closest star is 4 light years away. That means light takes 4 years to reach. Even if you could average half the speed of light, that's 8 years, one way. Anything you send is gone.
If I understand correctly, you're just basing that statement on climate change or war destroying us before we can do any better than Voyager, right? Because if we don't assume the destruction of humanity or the complete removal of our ability to make things leave Earth, then just based on "finite past vs. infinite future," it seems incredibly unlikely that we'd never be able to beat an extremely old project operating far beyond its designed scope.
Based on what? That we will never be able to make probes travelling faster than ~17km/s (relative to the Sun) that will eventually reach and overtake Voyager 1?
I certainly wouldn't bet against technological progress, and I say that as a complete doomer.
Well voyager depended on a solar system alignment that only happens every 175 years(?) so it'd be a while before we get that same advantage again. The longer it takes the further of a head start voyager gets?
That alignment is only necessary to do the Grand Tour, to visit all four outer planets in one mission. Voyager 1 actually didn't do the Grand Tour, it only visited Jupiter and Saturn, you're thinking of Voyager 2. This alignment is also not even necessary to attain the highest speed, Voyager 1 is even faster than Voyager 2.
A flyby of both Jupiter and Saturn can be done every two decades or so (the synodic period is 19.6 years)
The conjunction for the Grand Tour is once every 175 years. While you might be able to get a Jupiter and Saturn assist sooner, it is something that would take the right alignment and a mission to study the outer planets (rather than getting captured by Jupiter or Saturn for study of those planets and their moons).
You’ve given numbers for how fast New Horizons launched, and for how fast Voyager 1 got thanks to the 1-in-175-years boost, but is there an easy way to actually compare them?
IE either what speed Voyager 1 launched at excluding the gravity assists, or what speed New Horizons would have reached if it were launched 175 years after Voyager 1 (to take advantage of the same gravity assists)?
Starship could be refueled in orbit. That should then be able to reach those kind of velocities with enough capacity to even include a small 3rd stage inside with the payload.
Very true insofar as it's a description of Voyager communications. Voyager was 1970s radio engineering. Radio signals spread wide, so you need a big dish to catch it. These days we are using lasers, and laser divergence is several orders of magnitude smaller. And regardless of tech, relay enforces a minimum distance for any signal to spread.
This is a silly counterexample - why would we launch them that far apart? It’s a terrible idea for multiple reasons. We’d want them close together, with some redundancy as well, in case of failures.
What dish size would be required for a “cylindrical/tubular mesh” of probes, say, 1AU apart (ie Earth-Sun distance)? I’m pretty sure that would be manageable, but open to being wrong. (For reference, Voyager 1 is 169AU from Earth, but I have no idea how dish size vs. signal strength works: https://science.nasa.gov/mission/voyager/where-are-voyager-1...)
You could send a good amount of small probes and make them become the big antenna dish basically. As long as you cover the bases, you can have layers of "big antenna dishes" in onion layers.
And yes, the transmitters will need to be powerful enough be a distinct signal over the background of the star that is in the line of sight of the receiver / beyond the transmitter.
My understanding is that's a solved problem - NASA's Deep Space Optical Communication has demonstrated laser communication even with the sun in the background. Laser wavelength and modulation are noticeably different than a stars noise if you filter and just look for the wavelength and modulation of the laser, which is notably shorter and faster than most of the noise coming from the star.
We need quantum entanglement based communication. Maybe without full collapse, using weak measurements, like Alice continuously broadcasts a "retrocausal carrier wave" by sequencing planned future post-selection measurements on her entangled qubits, which backward-propagates through time-symmetric quantum evolution to create detectable perturbations in the present states, biasing Bob's qubits away from pure randomness to encode message patterns.
Both parties perform weak measurements on their qubits to extract these subtle signals without collapsing the entanglement, preserving high coherence across the stream. A quantum Maxwell's demon (e.g. many experiments but can be done: https://pubmed.ncbi.nlm.nih.gov/30185956/) then adaptively selects the strongest perturbations from the wave, filters out noise, and feeds them into error correction to reliably decode and amplify the full message.
The problem is each relay needs its own power source so it's not going to be as light and small as you would like. Solar power doesn't work very well outside of the solar system, or even really in the outer solar system.
On the plus side your big probe could push off of the small probe to give itself a further boost, also necessary because otherwise the small probes need thrusters to slow themselves to a stop.
You can't leave anything behind. That would need to be accelerated to 50,000 km/h or have even bigger rockets than launched Voyager in the first place.
Well, the voyager power source is still pretty good. But as I understand it the thermocouple that converts heat to electricity has degraded. Because the Pu-238 half life is 87 years so they wouldn't even be down to half yet..
I wonder if we can go the reverse direction, where instead of launching more probes from Earth to serve as relays, the spacecraft would launch physical media toward Earth packed with whatever data it has collected. Given advancements in data storage density, we could achieve higher bandwidth than what's possible with radios.
The logistics would be difficult since it involves catch those flying media, especially if the spacecraft were ejecting them as a form of propulsion, they might not even be flying toward Earth. I was just thinking how early spy satellites would drop physical film, and maybe there are some old ideas like those that are still worth trying today.
The spacecraft is moving away from the sun at escape velocity. How is it going to launch anything backwards and have it make it all the way back to earth?
With current probes being so "slow" (peak speed of the Voyager probes was on the order of 0.005% the speed of light) I wonder if even doing 10 probes at once per decade gets you more data back than working towards faster probe for less total time.
You could use this to create a relay in reverse order, but I also wonder if having a 50-100 year old relay would be any better than just using modern tech directly on the newest, fastest probe and then moving on to the next when there are enough improvements.
the post office has utility even if the messages have very high latency.
also if this probe network reduces the transmission costs to normal terrestrial levels (and not requiring , say, a 400kw tx dish..) it could drastically increases the utility of the link -- and all of this without discussing how much bandwidth a link network across the stars might possess compared to our current link to Voyager..
(this is all said with the presumption of a reason to have such distance communications channels.. )
You're exactly right and thank you for carefully reading! I very explicitly said that there was a multi year round trip for information even in the best case (e.g. Alpha Centauri), to get out ahead of the well-actually's.
As you noted, some of the gains could be signal power, redundancy, the ability to maintain a quality signal over arbitrary distance; but most importantly, seeing the universe from the perspective of the lead probe in the relay, some arbitrary distance away.
Wrote about the Voyager probes two days ago in my blog -
The two Voyager spacecraft are the greatest love letters humanity has ever sent into the void.
Voyager 2 actually launched first, on August 20, 1977, followed by Voyager 1 on September 5, 1977. Because Voyager 1 was on a faster, shorter trajectory (it used a rare alignment to slingshot past both Jupiter and Saturn quicker), it overtook its twin and became the farther, faster probe. As of 2025, Voyager 1 is the most distant human-made object ever, more than 24 billion kilometers away, still whispering data home at 160 bits per second.
Voyager 2 was the real beneficiary of the rare outer planet alignment, as it went on the famous Grand Tour, visiting all four of the giants. It did gravity assists at Jupiter, Saturn, and Uranus. [1] shows the rough velocity of V2 over time.
Voyager 1 was directed to perform a flyby of Titan, at the cost of being thrown out of the ecliptic and being unable to visit the ice giants like its sister. But this was deemed acceptable due to Titan's high science value.
That happened because Voyager 2 went over Neptune's north pole rather than an equatorial trajectory. Both to get a look at a giant planet's polar regions, and because that would get it closest to the moon Triton. So Voyager 2's trajectory got bent southward out of the ecliptic plane as a result of that.
While I'm here: why didn't Voyager 2 continue to slingshot to Pluto? The answer is that its trajectory would have had to bend by about 90° at Neptune, which would have required an apex closer to Neptune's center of mass than the planet's own radius - it would have crashed into the planet instead.
The two Voyager spacecraft are the greatest love letters humanity has ever sent into the void.
Voyager 2 actually launched first, on August 20, 1977, followed by Voyager 1 on September 5, 1977. Because Voyager 1 was on a faster, shorter trajectory (it used a rare alignment to slingshot past both Jupiter and Saturn quicker), it overtook its twin and became the farther, faster probe. As of 2025, Voyager 1 is the most distant human-made object ever, more than 24 billion kilometers away, still whispering data home at 160 bits per second.
Each spacecraft carries an identical 12-inch gold-plated copper phonograph record.
The contents:
- Greetings in 55 human languages.
- A message from UN Secretary-General at the time and one from U.S. President Jimmy Carter.
- 115 analog images encoded in the record’s grooves: how to build the stylus and play the record, the solar system’s location using 14 pulsars as galactic GPS, diagrams of human DNA, photos of a supermarket, a sunset, a fetus, people eating, licking ice cream, and dancing
The record is encased in an aluminum jacket with instructions etched on the cover: a map of the pulsars, the hydrogen atom diagram so aliens can decode the time units, and a tiny sample of uranium-238 so they can carbon-date how old the record is when they find it.
Sagan wanted the record to be a message in a bottle for a billion years. The spacecraft themselves are expected to outlive Earth. In a billion years, when the Sun swells into a red giant and maybe swallows Earth, the Voyagers will still be cruising the Milky Way, silent gold disks carrying blind, naked humans waving hello to a universe that may never wave back.
And it was Sagan who, in 1989, when Voyager 1 was already beyond Neptune and its cameras were scheduled to be turned off forever to save power, begged NASA for one last maneuver. On Valentine’s Day 1990, the spacecraft turned around, took 60 final images, and captured Earth as a single pale blue pixel floating in a scattered beam of sunlight — the photograph that gives the book its name and its soul.
It was the photograph that inspired this famous quote -
"Look again at that dot. That's here. That's home. That's us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every "superstar," every "supreme leader," every saint and sinner in the history of our species lived there-on a mote of dust suspended in a sunbeam.
The Earth is a very small stage in a vast cosmic arena. Think of the endless cruelties visited by the inhabitants of one corner of this pixel on the scarcely distinguishable inhabitants of some other corner, how frequent their misunderstandings, how eager they are to kill one another, how fervent their hatreds. Think of the rivers of blood spilled by all those generals and emperors so that, in glory and triumph, they could become the momentary masters of a fraction of a dot.
Our posturings, our imagined self-importance, the delusion that we have some privileged position in the Universe, are challenged by this point of pale light. Our planet is a lonely speck in the great enveloping cosmic dark. In our obscurity, in all this vastness, there is no hint that help will come from elsewhere to save us from ourselves.
The Earth is the only world known so far to harbor life. There is nowhere else, at least in the near future, to which our species could migrate. Visit, yes. Settle, not yet. Like it or not, for the moment the Earth is where we make our stand.
It has been said that astronomy is a humbling and character-building experience. There is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world. To me, it underscores our responsibility to deal more kindly with one another, and to preserve and cherish the pale blue dot, the only home we've ever known. "
That picture almost didn’t happen. NASA said it was pointless, the cameras were old, the images would be useless. Sagan argued it would be the first time any human ever saw our world from outside the solar system. He won. The cameras were powered up one last time, the portrait was taken, and then they were shut down forever.
Wow, this gives a reflection about our future. The nearest potentially habitable planet known is Proxima Centauri b, which orbits the red dwarf star Proxima Centauri about 4 light‑years from Earth (at least it is in a habitable zone of its star) [1]. So we don't have a choice actually except protecting and make sure our planet survives. That's regardless if it really would be able to support life as we know or not (probably not).
In my opinion, if we really want a presence off of earth we'd be better off building larger and larger space habitats and bootstrapping a mining industry in space.
Agreed. Once it becomes commercially viable to start building things in space, it'll take off on its own. There will be constant pressure to build faster, safer, more capable craft. Whether that will lead to something like FTL isn't possible to know, but at the very least it's a step towards a space-faring civilization.
Gliese 710 will pass 0.17 light years from us in a bit over 1M years. If we can colonize mars and build some infrastructure in the solar system by then, we should have an OK shot at getting something there to stay. It'll be 62 light days away.
I have an optimistic view that building underground facilities on Mars/Lunar might not be a far-stretched idea. But I have never done any research into the idea so not whether it works or not.
Basically, reducing costs and tech requirements by going underground (since it is underground we do not need to terraform the planet, and it is less likely to leak oxygen to external environment). Digging dirts and stones is a solvable problem. So optimistically I believe this is just an engineering/cost problem.
Almost understating the point if anything. Mars is less habitable than the bottom of the Marina trench. An environment that could kill every person on earth in a millisecond.
Yes, the distances are mind-boggling. There are a few somewhat realistic solutions for making such a trip in the forseeable future. If you send something of significant mass, it is certain to take a long time. So we're either talking generation ships(§), embryo space colonization (growing into adults en route or at destination) or hibernation. That or a breakthrough in fundamental physics.
--
(§) Something like O'Neill cylinders with fusion as energy source could work
This old video is a beautiful and astounding demonstration of just how vastly, hugely, mind-bogglingly big the Universe is, and where in all this endless space our dear favourite little Pale Blue Dot (Earth) resides:
We all Earthlings are extremely lucky to be alive and thriving (or trying to) in such a beautiful bountiful rarest-of-rare ecosystem that somehow survived and thrived despite all the vagaries and vastness of spacetime.
Space is cool, and I support the scientific work some of its pioneers discover. But the category of people who believe space travel is somehow the solution to problems on Earth give me headaches.
Even if we find another habitable planet, figure out how to get there, start a colony, what in the world makes us think we won't fuck up that planet like we've fucked up this one?
Whoever is currently alive won't live to see the absolute worse that earth is going to be in upcoming centuries, if the human civilization even survives until then
I try not to succumb to this attitude. Humans are remarkably able to build systems and technology to solve complex problems. The fact that we aren't making the needed changes now fast enough doesn't rule out that we might as it becomes more apparently necessary, or that some new plan will emerge which helps dramatically.
But we also cannot get complacent thinking that it's future generations problem. We need a breakthrough yesterday.
When Andromeda and the Milky Way collide there will be no planets or solar systems that collide from either system. A fascinating fact in in own right, it's simply due to the scale of the galaxies and that they are mostly composed of empty space.
Unless we find the means to manipulate our own star or the orbit of Earth we most likely will not be around at that time. The sun's increased luminosity will boil us way earlier.
Given that there is very little interest in developing commons here on earth (especially new types of commons from whole cloth), the shape that "making uninhabitable planets habitable" would likely take is that of living in bubbles rather than some kind of broad-scale terraforming. This would intrinsically shape society towards top-down authoritarian control, rather than allowing for distributed individual liberty. In this light, Earth's bountiful distributed air, water, and wildlife should be viewed as a technological-society-bootstrapping resource similar to easily-accessible oil and coil stored energy deposits.
You often hear about the fatality rate per 100 million or 1 billion passenger miles in transportation statistics, but over the last 15 years, U.S. airlines have averaged less than 1 fatality per passenger light-year traveled
Technically when tweeted for the given selective timespan, but no longer true since the crash this year in DC.
Still, mind blowing. When fact checking this I learned we went over 2 passenger light years worth of airline travel with no fatalities during that time frame. Incredible safety record. Real shame this year has been so terrible for our reputation.
Make the model scale to be 10000000 (10 million). The sun is a chunky 139 meters in diameter. Earth is 15 km (9 miles) away. Pluto is 587 km (365 miles) away. The speed of light is 107 kph (67 mph).
Alpha Centauri is 4.1 million km (2.5 million miles) away... that is 10 times the earth moon distance.
Another comparison... Voyager 1 is moving at 30 light minutes per year. (Andromeda galaxy is approaching the Milky Way at 3.2 light hours per year)
If you can figure out a way to apply thrust that doesn't require you to lug mass with you and throw it out the back of your spacecraft you will open up the stars to exploration. If not the rocket equation will wreck your plans every time.
If there are creatures who could live longer than that, perhaps by hibernating or just having really long lifetimes, space exploration is feasible with slow craft.
I believe there's a semi-common sci-fi construct to send probes containing human brain dumps running on silicon to these far away star systems. Just hit pause until a week before arrival :).
Próxima Centauri is about 250 million years older than our sun. Makes it not-impossible their earth like planet had advanced entities capable of sending their own voyager towards earth. Possibly it flew by while we were still in our Mesozoic Era and all they saw were dinosaurs.
Here is a funny thought experiment - the distance from Voyager to Earth varies by approximately 16 light minutes throughout the year. Why? Because it takes ~8 minutes for light to go from the Sun to the Earth, so presuming the Voyager is roughly planar with the Sun/Earth (I'm just assuming yes), that gives a variance of ~16 minutes depending on where the earth is on its orbit.
Now I'm presuming they aren't using the actual Earth position, but rather an average Earth position (which is basically just the Sun's position). Since Voyager is ~30 light minutes away from being 1 light-day away, that means this ~16 minute change can affect our 1 light-day mark by up to ~6 months!
Now the question is, what time is it in voyager 1? With time dilation, the "now" on Voyager is out of sync with our now. I was watching star wars recently and when Han Solo casually say "we should be in Alderaan at 0200 hours", I paused for a second. What does that even mean [0]? Traveling through space is challenging today, but after we figure that out, we will have to face the problem of time keeping across the galaxy.
> With time dilation, the "now" on Voyager is out of sync with our now
A couple minutes [1].
> we will have to face the problem of time keeping across the galaxy
Not really. Barring relativistic travel, it’s not dissimilar from the problem seagoing voyagers faced on long trade routes. Ship time is set based on the convenience of the passengers and the route.
I've been reading such posts for years. Every few months, "Voyager 1 is the most distant man-made object ever!" or "Voyager 1 about to leave the Solar System!"
Trump will turn this into "American spaceships, the best in the world, world class probes, now light years away from Earth to find who knows what treasures lie there."
"Space is big. Really big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean you may think it's a long way down the road to the chemist, but that's just peanuts to space."
This old video is a beautiful and astounding demonstration of just how vastly, hugely, mind-bogglingly big the Universe is, and where in all this endless space our dear favourite little Pale Blue Dot (Earth) resides:
We all Earthlings are extremely lucky to be alive and thriving (or trying to) in such a beautiful bountiful rarest-of-rare ecosystem that somehow survived and thrived despite all the vagaries and vastness of spacetime.
V'ger raises the question of how Starfleet missed it for so long, given how slow the Voyager probes were and how near-future the Star Trek timeline is.
When I read stats like this I realize how stuck in this solar system we are. I wonder if billionaires would care for the planet more if they knew that Earth is honestly just it for humans, for maybe forever.
"From this distant vantage point, the Earth might not seem of any particular interest. But for us, it's different. Consider again that dot. That's here. That's home. That's us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every "superstar", every "supreme leader", every saint and sinner in the history of our species lived there – on a mote of dust suspended in a sunbeam. "
Nah, the whole second-Earth, terraforming nonsense is pure rationalization for whatever they want to do. If they weren’t using that as a post hoc justification, they’d just land on something else.
I’m not aware of any organisation or individual that has actual plans (backed with actual investment) for terraforming anything. This is a straw man argument.
You people should stop demonizing billionaires. You're the ones burning the fossil fuels, not them. If their wealth way distributed among more people then those people would spend it damaging the environment which is what people generally do with their money anyway.
This. It's not a spatial problem, it's a temporal one. They are somewhat aware there will be nowhere to run to (I say somewhat because they still spend millions in luxury bunkers), they are just betting that it won't get really bad during their lifetime, maybe their kids lifetime for the more empathetic ones.
Not that we would literally do this with Voyager, but it makes me wonder at the potential utility of a string of probes, one sent every couple of [insert correct time interval, decades, centuries?], to effectively create a communication relay stretching out into deep space somewhere.
My understanding with the Voyagers 1 and 2 is (a) they will run out of power before they would ever get far enough to benefit from a relay and (b) they benefited from gravity slingshots due to planetary alignments that happen only once every 175 years.
So building on the Voyager probes is a no-go. But probes sent toward Alpha Centauri that relay signals? Toward the center of the Milky Way? Toward Andromeda? Yes it would take time scales far beyond human lifetimes to build out anything useful, and even at the "closest" scales it's a multi year round trip for information but I think Voyager, among other things, was meant to test our imaginations, our sense of possible and one thing they seem to naturally imply is the possibility of long distance probe relays.
Edit: As others rightly note, the probes would have to communicate with lasers, not with the 1970s radio engineering that powered Voyagers 1 and 2.
What you are describing has been proposed before, for example within context of projects like Breakthrough Starshot. In that the case the idea is to launch thousands of probes, each weighing only a few grams or less, and accelerating them to an appreciable fraction of the speed of light using solar sails and (powerful) earth-based lasers. The probes could reach alpha centauri within 20-30 years. There seems to be some debate though about whether cross-links between probes to enable relaying signals is ever practical from a power and mass perspective vs a single very large receiver on earth.
Indeed. I think the main reason to send thousands of probes is increasing the odds that they will survive the trip and also be in the right position to gather usable data to transmit back.
Also once you have created the infrastructure of hundreds or thousands of very powerful lasers to accelerate the tiny probes to incredibel speeds, sending many probes instead of a few doesn't add much to the cost anyway.
If I don't recall wrongly, Breakthrough Starshot was not a means for commnunicaiton relay as he describes.
No one likes to think this but it’s very possible voyager is the farthest humanity will go. In fact realistically speaking it is the far more likeliest possibility.
Provided we don't wipe ourselves out, there's no technical reason why we can't go interstellar. It's just way harder and more energy intensive than most people imagine, so I doubt it's happening any time in the next few hundred years.
But we already understand the physics and feasibility of "slow" (single-digit fractions of c) interstellar propulsion systems. Nuclear pulse propulsion and fission fragment rockets require no new physics or exotic engineering leaps and could propel a probe to the stars, if one was so inclined. Fusion rockets would do a bit better, although we'd have to crack the fusion problem first. These sorts of things are well out of today's technology, but it's not unforeseeable in a few centuries. You could likewise imagine a generation ship a few centuries after that powered by similar technology.
The prerequisite for interstellar exploration is a substantial exploitation of our solar system's resources: terraform Mars, strip mine the asteroid belt, build giant space habitats like O'Neill cylinders. But if we ever get to that point - and I think it's reasonable to think we will, given enough time - an interstellar mission becomes the logical next step.
Will we ever get to the point where traveling between the stars is commonplace? No, I doubt it. But we may get to the point where once-in-a-century colonization missions are possible, and if that starts, there's no limit to humanity colonizing the Milky Way given a few million years.
The other thing we could do to explore the galaxy is to become biologically something we would no longer recognize. We're viewing this from the lens of "humanity must remain biologically static" but I want to point out that that's not physically necessary here and that there is life on Earth that can stop its metabolism for decades and things like that.
Yes, it's incredibly easy to do these things once you've done all these other, incredibly difficult things first.
The furthest a human has been is 250k miles (far side of the moon). The fastest a human has traveled is only 0.0037% the speed of light.
The ISS is about 260 miles from the Earth. At that height, the gravity is actually roughly the same as on the surface, it's only because it is in constant freefall that you experience weightlessness on it.
Mars is 140 million miles away. And not exactly hospitable.
I like how you treat "the fusion problem" with a throwaway, "Yeah, we'd have to solve that" as if we just haven't sufficiently applied ourselves yet.
All of those incredibly difficult things we have not even begun to do are the technical reasons we have not gone interstellar and may be the reason we will never do so.
And even if we solve the issue of accelerating a human being to acceptable speeds to reach another star, the next closest star is 4 light years away. That means light takes 4 years to reach. Even if you could average half the speed of light, that's 8 years, one way. Anything you send is gone.
If I understand correctly, you're just basing that statement on climate change or war destroying us before we can do any better than Voyager, right? Because if we don't assume the destruction of humanity or the complete removal of our ability to make things leave Earth, then just based on "finite past vs. infinite future," it seems incredibly unlikely that we'd never be able to beat an extremely old project operating far beyond its designed scope.
Many reasons why. The probability is based on many many many factors. What you mentioned is just a fraction of the factors.
If we do ever reach that distance again it will be even less likely we do it for a third time.
This is all based on the assumption that we are not able to build spacecrafts with faster speeds.
There was simply no incentive to do so yet. But one day we will build faster spacecrafts and then we are going to overtake it quite quickly.
Based on what? That we will never be able to make probes travelling faster than ~17km/s (relative to the Sun) that will eventually reach and overtake Voyager 1?
I certainly wouldn't bet against technological progress, and I say that as a complete doomer.
Well voyager depended on a solar system alignment that only happens every 175 years(?) so it'd be a while before we get that same advantage again. The longer it takes the further of a head start voyager gets?
That alignment is only necessary to do the Grand Tour, to visit all four outer planets in one mission. Voyager 1 actually didn't do the Grand Tour, it only visited Jupiter and Saturn, you're thinking of Voyager 2. This alignment is also not even necessary to attain the highest speed, Voyager 1 is even faster than Voyager 2.
A flyby of both Jupiter and Saturn can be done every two decades or so (the synodic period is 19.6 years)
https://en.wikipedia.org/wiki/Grand_Tour_program
The headstart doesn't really matter, anything faster than Voyager will catch up eventually
Voyager 1 is traveling at 16.9 km/s.
New Horizons (which has the distinguishing feature of being the fastest human-made object ever launched from earth https://www.scientificamerican.com/blog/life-unbounded/the-f... ) is traveling at 12.6 km/s.
The key part there is that it got multiple gravity assists as part of the Grand Tour https://en.wikipedia.org/wiki/Grand_Tour_program . You can see the heliocentric velocity https://space.stackexchange.com/questions/10346/why-did-voya... https://www.americanscientist.org/article/the-voyagers-odyss...
The conjunction for the Grand Tour is once every 175 years. While you might be able to get a Jupiter and Saturn assist sooner, it is something that would take the right alignment and a mission to study the outer planets (rather than getting captured by Jupiter or Saturn for study of those planets and their moons).
While I would love to see a FOCAL mission https://en.wikipedia.org/wiki/FOCAL_(spacecraft) which would have reason for such a path, I doubt any such telescope would launched... this century.
You’ve given numbers for how fast New Horizons launched, and for how fast Voyager 1 got thanks to the 1-in-175-years boost, but is there an easy way to actually compare them?
IE either what speed Voyager 1 launched at excluding the gravity assists, or what speed New Horizons would have reached if it were launched 175 years after Voyager 1 (to take advantage of the same gravity assists)?
Starship could be refueled in orbit. That should then be able to reach those kind of velocities with enough capacity to even include a small 3rd stage inside with the payload.
Not useful, because the signal are too weak to be picked up probe to probe.
On earth, the tiny signal from Voyager at this distance is picked up by dish the size of a football field; same with sending of the signal.
Very true insofar as it's a description of Voyager communications. Voyager was 1970s radio engineering. Radio signals spread wide, so you need a big dish to catch it. These days we are using lasers, and laser divergence is several orders of magnitude smaller. And regardless of tech, relay enforces a minimum distance for any signal to spread.
This is a silly counterexample - why would we launch them that far apart? It’s a terrible idea for multiple reasons. We’d want them close together, with some redundancy as well, in case of failures.
What dish size would be required for a “cylindrical/tubular mesh” of probes, say, 1AU apart (ie Earth-Sun distance)? I’m pretty sure that would be manageable, but open to being wrong. (For reference, Voyager 1 is 169AU from Earth, but I have no idea how dish size vs. signal strength works: https://science.nasa.gov/mission/voyager/where-are-voyager-1...)
You could send a good amount of small probes and make them become the big antenna dish basically. As long as you cover the bases, you can have layers of "big antenna dishes" in onion layers.
The dish isn't the size of a football field, it's a 70 meter dish (football field is 110 meters), it can however, transmit at 400 kilowatts of power
> the tiny signal from Voyager at this distance is picked up by dish the size of a football field
Lots of small fishes can resemble a large fish.
Laser communication could potentially address some of those issues.
Maybe, but if your probe is heading directly towards another solar system then it will be backlit by its destination.
https://space.stackexchange.com/questions/33338/why-is-the-o... is a neat question that addresses this issue.
And yes, the transmitters will need to be powerful enough be a distinct signal over the background of the star that is in the line of sight of the receiver / beyond the transmitter.
My understanding is that's a solved problem - NASA's Deep Space Optical Communication has demonstrated laser communication even with the sun in the background. Laser wavelength and modulation are noticeably different than a stars noise if you filter and just look for the wavelength and modulation of the laser, which is notably shorter and faster than most of the noise coming from the star.
What if the probes carry smaller probes left behind at specific intervals that act as repeaters?
These baby probes could unfold a larger spiderweb antenna the size of a tennis court.
We need quantum entanglement based communication. Maybe without full collapse, using weak measurements, like Alice continuously broadcasts a "retrocausal carrier wave" by sequencing planned future post-selection measurements on her entangled qubits, which backward-propagates through time-symmetric quantum evolution to create detectable perturbations in the present states, biasing Bob's qubits away from pure randomness to encode message patterns.
Both parties perform weak measurements on their qubits to extract these subtle signals without collapsing the entanglement, preserving high coherence across the stream. A quantum Maxwell's demon (e.g. many experiments but can be done: https://pubmed.ncbi.nlm.nih.gov/30185956/) then adaptively selects the strongest perturbations from the wave, filters out noise, and feeds them into error correction to reliably decode and amplify the full message.
The problem is each relay needs its own power source so it's not going to be as light and small as you would like. Solar power doesn't work very well outside of the solar system, or even really in the outer solar system.
On the plus side your big probe could push off of the small probe to give itself a further boost, also necessary because otherwise the small probes need thrusters to slow themselves to a stop.
You can't leave anything behind. That would need to be accelerated to 50,000 km/h or have even bigger rockets than launched Voyager in the first place.
Football field might even be too small…
Wasn’t Arecibo used for Voyager?
It might have from time to time... but it had limited ability to track.
As I type this, DNS Now is currently receiving data from Voyager 1. https://eyes.nasa.gov/apps/dsn-now/dsn.html
https://imgur.com/a/kXbhRsj for a screen shot of the relevant data.
The antenna data is https://www.mdscc.nasa.gov/index.php/en/dss-63-2/
Well, the voyager power source is still pretty good. But as I understand it the thermocouple that converts heat to electricity has degraded. Because the Pu-238 half life is 87 years so they wouldn't even be down to half yet..
I wonder if we can go the reverse direction, where instead of launching more probes from Earth to serve as relays, the spacecraft would launch physical media toward Earth packed with whatever data it has collected. Given advancements in data storage density, we could achieve higher bandwidth than what's possible with radios.
The logistics would be difficult since it involves catch those flying media, especially if the spacecraft were ejecting them as a form of propulsion, they might not even be flying toward Earth. I was just thinking how early spy satellites would drop physical film, and maybe there are some old ideas like those that are still worth trying today.
The spacecraft is moving away from the sun at escape velocity. How is it going to launch anything backwards and have it make it all the way back to earth?
I think they're working on laser data transmission.
With current probes being so "slow" (peak speed of the Voyager probes was on the order of 0.005% the speed of light) I wonder if even doing 10 probes at once per decade gets you more data back than working towards faster probe for less total time.
You could use this to create a relay in reverse order, but I also wonder if having a 50-100 year old relay would be any better than just using modern tech directly on the newest, fastest probe and then moving on to the next when there are enough improvements.
Hmm, do you realize, that even if you have 1B probes everywhere. You're still bound by speed of light communication speed, right?
It's faster than probe speed in this age, yeah. But still not enough, if we're talking distances to other specific planets, stars, etc.
Two possible ways to solve this, humans will become immortal or speed of light bypass method will be discovered.
the post office has utility even if the messages have very high latency.
also if this probe network reduces the transmission costs to normal terrestrial levels (and not requiring , say, a 400kw tx dish..) it could drastically increases the utility of the link -- and all of this without discussing how much bandwidth a link network across the stars might possess compared to our current link to Voyager..
(this is all said with the presumption of a reason to have such distance communications channels.. )
Seems like the problem OP is trying to solve for here is not latency, it's signal power and redundancy.
You're exactly right and thank you for carefully reading! I very explicitly said that there was a multi year round trip for information even in the best case (e.g. Alpha Centauri), to get out ahead of the well-actually's.
As you noted, some of the gains could be signal power, redundancy, the ability to maintain a quality signal over arbitrary distance; but most importantly, seeing the universe from the perspective of the lead probe in the relay, some arbitrary distance away.
Wrote about the Voyager probes two days ago in my blog - The two Voyager spacecraft are the greatest love letters humanity has ever sent into the void.
Voyager 2 actually launched first, on August 20, 1977, followed by Voyager 1 on September 5, 1977. Because Voyager 1 was on a faster, shorter trajectory (it used a rare alignment to slingshot past both Jupiter and Saturn quicker), it overtook its twin and became the farther, faster probe. As of 2025, Voyager 1 is the most distant human-made object ever, more than 24 billion kilometers away, still whispering data home at 160 bits per second.
Voyager 2 was the real beneficiary of the rare outer planet alignment, as it went on the famous Grand Tour, visiting all four of the giants. It did gravity assists at Jupiter, Saturn, and Uranus. [1] shows the rough velocity of V2 over time.
Voyager 1 was directed to perform a flyby of Titan, at the cost of being thrown out of the ecliptic and being unable to visit the ice giants like its sister. But this was deemed acceptable due to Titan's high science value.
[1] https://commons.wikimedia.org/wiki/File:Voyager_2_-_velocity...
To save someone two seconds of searching,
NASA animation of Voyager 2's trajectory (time in the bottom-left corner): https://youtu.be/l8TA7BU2Bvo
This is great. I did not realize Voyager 2 also left the ecliptic at the end of its tour.
That happened because Voyager 2 went over Neptune's north pole rather than an equatorial trajectory. Both to get a look at a giant planet's polar regions, and because that would get it closest to the moon Triton. So Voyager 2's trajectory got bent southward out of the ecliptic plane as a result of that.
While I'm here: why didn't Voyager 2 continue to slingshot to Pluto? The answer is that its trajectory would have had to bend by about 90° at Neptune, which would have required an apex closer to Neptune's center of mass than the planet's own radius - it would have crashed into the planet instead.
And that love letter came with a very nice mixtape. https://en.wikipedia.org/wiki/Voyager_Golden_Record
Yea, I mentioned that too.
Extended piece from my blog.
The two Voyager spacecraft are the greatest love letters humanity has ever sent into the void.
Voyager 2 actually launched first, on August 20, 1977, followed by Voyager 1 on September 5, 1977. Because Voyager 1 was on a faster, shorter trajectory (it used a rare alignment to slingshot past both Jupiter and Saturn quicker), it overtook its twin and became the farther, faster probe. As of 2025, Voyager 1 is the most distant human-made object ever, more than 24 billion kilometers away, still whispering data home at 160 bits per second.
Each spacecraft carries an identical 12-inch gold-plated copper phonograph record.
The contents:
- Greetings in 55 human languages.
- A message from UN Secretary-General at the time and one from U.S. President Jimmy Carter.
- 115 analog images encoded in the record’s grooves: how to build the stylus and play the record, the solar system’s location using 14 pulsars as galactic GPS, diagrams of human DNA, photos of a supermarket, a sunset, a fetus, people eating, licking ice cream, and dancing
The record is encased in an aluminum jacket with instructions etched on the cover: a map of the pulsars, the hydrogen atom diagram so aliens can decode the time units, and a tiny sample of uranium-238 so they can carbon-date how old the record is when they find it.
Sagan wanted the record to be a message in a bottle for a billion years. The spacecraft themselves are expected to outlive Earth. In a billion years, when the Sun swells into a red giant and maybe swallows Earth, the Voyagers will still be cruising the Milky Way, silent gold disks carrying blind, naked humans waving hello to a universe that may never wave back.
And it was Sagan who, in 1989, when Voyager 1 was already beyond Neptune and its cameras were scheduled to be turned off forever to save power, begged NASA for one last maneuver. On Valentine’s Day 1990, the spacecraft turned around, took 60 final images, and captured Earth as a single pale blue pixel floating in a scattered beam of sunlight — the photograph that gives the book its name and its soul.
It was the photograph that inspired this famous quote -
"Look again at that dot. That's here. That's home. That's us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every "superstar," every "supreme leader," every saint and sinner in the history of our species lived there-on a mote of dust suspended in a sunbeam.
The Earth is a very small stage in a vast cosmic arena. Think of the endless cruelties visited by the inhabitants of one corner of this pixel on the scarcely distinguishable inhabitants of some other corner, how frequent their misunderstandings, how eager they are to kill one another, how fervent their hatreds. Think of the rivers of blood spilled by all those generals and emperors so that, in glory and triumph, they could become the momentary masters of a fraction of a dot.
Our posturings, our imagined self-importance, the delusion that we have some privileged position in the Universe, are challenged by this point of pale light. Our planet is a lonely speck in the great enveloping cosmic dark. In our obscurity, in all this vastness, there is no hint that help will come from elsewhere to save us from ourselves.
The Earth is the only world known so far to harbor life. There is nowhere else, at least in the near future, to which our species could migrate. Visit, yes. Settle, not yet. Like it or not, for the moment the Earth is where we make our stand.
It has been said that astronomy is a humbling and character-building experience. There is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world. To me, it underscores our responsibility to deal more kindly with one another, and to preserve and cherish the pale blue dot, the only home we've ever known. "
That picture almost didn’t happen. NASA said it was pointless, the cameras were old, the images would be useless. Sagan argued it would be the first time any human ever saw our world from outside the solar system. He won. The cameras were powered up one last time, the portrait was taken, and then they were shut down forever.
That legacy of the Pale Blue Dot has been something that has been repeated to remind us again. I personally like the Cassini one - https://science.nasa.gov/science-research/earth-science/23ju...
There's also the MESSENGER family portrait https://science.nasa.gov/resource/a-solar-system-family-port...
Wow, this gives a reflection about our future. The nearest potentially habitable planet known is Proxima Centauri b, which orbits the red dwarf star Proxima Centauri about 4 light‑years from Earth (at least it is in a habitable zone of its star) [1]. So we don't have a choice actually except protecting and make sure our planet survives. That's regardless if it really would be able to support life as we know or not (probably not).
[1] https://science.nasa.gov/resource/proxima-b-3d-model/
I think there are a few movies that made me realize how much the space is vast, empty and adverse to life.
I think it would be nice for people to take a look at them:
- Aniara (2018)
- High Life (2018)
and maybe in a less artistic view:
- Powers of Ten (1977) yt: https://www.youtube.com/watch?v=0fKBhvDjuy0
I showed my 6 year old son Powers of Ten a few nights ago and I think I accidentally gave him an existential crisis.
In my opinion, if we really want a presence off of earth we'd be better off building larger and larger space habitats and bootstrapping a mining industry in space.
Daniel Suarez [1] has written a book where he imagined how this could happen (Delta-v)
[1]: https://en.wikipedia.org/wiki/Daniel_Suarez_(author)
P.S. Read a lot of his book, great author
> if we really want a presence off of earth we'd be better off building larger and larger space habitats and bootstrapping a mining industry in space
This turns entirely on how human biology works in zero versus low gravity. (Same for spin versus natural, or linear, gravity.)
The experiments we need to be doing is building and launching space stations and planetary bases for mice.
I can't wait for all the studies making the news that end with "in mice in space"
Agreed. Once it becomes commercially viable to start building things in space, it'll take off on its own. There will be constant pressure to build faster, safer, more capable craft. Whether that will lead to something like FTL isn't possible to know, but at the very least it's a step towards a space-faring civilization.
Gliese 710 will pass 0.17 light years from us in a bit over 1M years. If we can colonize mars and build some infrastructure in the solar system by then, we should have an OK shot at getting something there to stay. It'll be 62 light days away.
I have an optimistic view that building underground facilities on Mars/Lunar might not be a far-stretched idea. But I have never done any research into the idea so not whether it works or not.
Basically, reducing costs and tech requirements by going underground (since it is underground we do not need to terraform the planet, and it is less likely to leak oxygen to external environment). Digging dirts and stones is a solvable problem. So optimistically I believe this is just an engineering/cost problem.
Mars is less habitable than the least habitable state we could let the earth in without being extinct. This is silly.
Almost understating the point if anything. Mars is less habitable than the bottom of the Marina trench. An environment that could kill every person on earth in a millisecond.
Yes, the distances are mind-boggling. There are a few somewhat realistic solutions for making such a trip in the forseeable future. If you send something of significant mass, it is certain to take a long time. So we're either talking generation ships(§), embryo space colonization (growing into adults en route or at destination) or hibernation. That or a breakthrough in fundamental physics.
--
(§) Something like O'Neill cylinders with fusion as energy source could work
This old video is a beautiful and astounding demonstration of just how vastly, hugely, mind-bogglingly big the Universe is, and where in all this endless space our dear favourite little Pale Blue Dot (Earth) resides:
https://m.youtube.com/watch?v=X-3Oq_82XNA
We all Earthlings are extremely lucky to be alive and thriving (or trying to) in such a beautiful bountiful rarest-of-rare ecosystem that somehow survived and thrived despite all the vagaries and vastness of spacetime.
Space is cool, and I support the scientific work some of its pioneers discover. But the category of people who believe space travel is somehow the solution to problems on Earth give me headaches.
Even if we find another habitable planet, figure out how to get there, start a colony, what in the world makes us think we won't fuck up that planet like we've fucked up this one?
Whoever is currently alive won't live to see the absolute worse that earth is going to be in upcoming centuries, if the human civilization even survives until then
I try not to succumb to this attitude. Humans are remarkably able to build systems and technology to solve complex problems. The fact that we aren't making the needed changes now fast enough doesn't rule out that we might as it becomes more apparently necessary, or that some new plan will emerge which helps dramatically.
But we also cannot get complacent thinking that it's future generations problem. We need a breakthrough yesterday.
Well I guess real end of the world will come around when we crash with Andromeda.
When Andromeda and the Milky Way collide there will be no planets or solar systems that collide from either system. A fascinating fact in in own right, it's simply due to the scale of the galaxies and that they are mostly composed of empty space.
Unless we find the means to manipulate our own star or the orbit of Earth we most likely will not be around at that time. The sun's increased luminosity will boil us way earlier.
Or we learn how to make uninhabitable planets habitable. Would also help us “save” this one.
(Funny how we say “save the planet” when we really mean “save people/complex life”).
Given that there is very little interest in developing commons here on earth (especially new types of commons from whole cloth), the shape that "making uninhabitable planets habitable" would likely take is that of living in bubbles rather than some kind of broad-scale terraforming. This would intrinsically shape society towards top-down authoritarian control, rather than allowing for distributed individual liberty. In this light, Earth's bountiful distributed air, water, and wildlife should be viewed as a technological-society-bootstrapping resource similar to easily-accessible oil and coil stored energy deposits.
Site is down? Archive: https://archive.is/55yNp
Headline is also misleading. It will do so in November 2026, about a year from now.
well, that's only about 30 light-minutes left
>Site is down?
They got Slashdotted ;-)
https://en.wikipedia.org/wiki/Slashdot_effect
We are flying "faster" on earth.
You often hear about the fatality rate per 100 million or 1 billion passenger miles in transportation statistics, but over the last 15 years, U.S. airlines have averaged less than 1 fatality per passenger light-year traveled
https://x.com/RyanRadia/status/1764868263903723874
Technically when tweeted for the given selective timespan, but no longer true since the crash this year in DC.
Still, mind blowing. When fact checking this I learned we went over 2 passenger light years worth of airline travel with no fatalities during that time frame. Incredible safety record. Real shame this year has been so terrible for our reputation.
Yes, when I saw the tweet, I thought the next crash might be near, and then happened DC soon after.
50 years for 1 light day... so to arrive Alpha Centauri that is 4.2 light years far away... 76549 years and 364 days :-)
One of the neat things that I've stumbled across is https://thinkzone.wlonk.com/SS/SolarSystemModel.php
Make the model scale to be 10000000 (10 million). The sun is a chunky 139 meters in diameter. Earth is 15 km (9 miles) away. Pluto is 587 km (365 miles) away. The speed of light is 107 kph (67 mph).
Alpha Centauri is 4.1 million km (2.5 million miles) away... that is 10 times the earth moon distance.
Another comparison... Voyager 1 is moving at 30 light minutes per year. (Andromeda galaxy is approaching the Milky Way at 3.2 light hours per year)
Less than that is you are constantly accelerating.
If you can figure out a way to apply thrust that doesn't require you to lug mass with you and throw it out the back of your spacecraft you will open up the stars to exploration. If not the rocket equation will wreck your plans every time.
Why?
75k years in geological timescales is nothing.
If there are creatures who could live longer than that, perhaps by hibernating or just having really long lifetimes, space exploration is feasible with slow craft.
Longer than that if you are constantly decelerating.
And exactly that if you're talking about Voyager 1, which is on a ballistic trajectory.
I believe there's a semi-common sci-fi construct to send probes containing human brain dumps running on silicon to these far away star systems. Just hit pause until a week before arrival :).
We're never getting out of this solar system, are we?
Haha, never doubt science! You never know. Centuries ago, humans then would have regarded today's technological feats as impossible.
But, yeah, I don't think we are ever leaving this solar system. Lol
If Voyager could stay operational and keep its speed of ~61,000 km/hr, it would reach the nearest star (Proxima Centauri) in about 72,000 years.
My mind understands the numbers, but can't grasp them.
For reference, the oldest cave drawings we know of were made by neanderthals around ~70,000 years ago [0].
[0] https://www.southampton.ac.uk/news/2018/02/neanderthals-art....
Próxima Centauri is about 250 million years older than our sun. Makes it not-impossible their earth like planet had advanced entities capable of sending their own voyager towards earth. Possibly it flew by while we were still in our Mesozoic Era and all they saw were dinosaurs.
No, it would no reach that star. It is not aimed at it but at the constellation Ophiuchus.
Here is a funny thought experiment - the distance from Voyager to Earth varies by approximately 16 light minutes throughout the year. Why? Because it takes ~8 minutes for light to go from the Sun to the Earth, so presuming the Voyager is roughly planar with the Sun/Earth (I'm just assuming yes), that gives a variance of ~16 minutes depending on where the earth is on its orbit.
Now I'm presuming they aren't using the actual Earth position, but rather an average Earth position (which is basically just the Sun's position). Since Voyager is ~30 light minutes away from being 1 light-day away, that means this ~16 minute change can affect our 1 light-day mark by up to ~6 months!
At current pace, Voyager 1 will have taken 49 Earth years to reach one light-day.
That means it will reach a light year in approximately the Earth year 19,860.
This is an absurdly simplified article :/ Wikipedia is way better and more technical.
I hope the Voyagers are not the furthest man-made item that we send into the universe in the whole civilization.
also discussed at https://news.ycombinator.com/item?id=45908483
What happens if Voyager decides to go back home?
How is the link with earth maintained at this distance? Is it really a powerful transmitter that sends signals without attenuation?
Now the question is, what time is it in voyager 1? With time dilation, the "now" on Voyager is out of sync with our now. I was watching star wars recently and when Han Solo casually say "we should be in Alderaan at 0200 hours", I paused for a second. What does that even mean [0]? Traveling through space is challenging today, but after we figure that out, we will have to face the problem of time keeping across the galaxy.
[0]: https://idiallo.com/blog/galactic-timekeeping
> With time dilation, the "now" on Voyager is out of sync with our now
A couple minutes [1].
> we will have to face the problem of time keeping across the galaxy
Not really. Barring relativistic travel, it’s not dissimilar from the problem seagoing voyagers faced on long trade routes. Ship time is set based on the convenience of the passengers and the route.
[1] https://space.stackexchange.com/questions/56055/if-voyager-1...
No, not "About to". It's this time "next year".
> No, not "About to". It's this time "next year".
48 years in space and a light-day from Earth? I think it qualifies for "about to" :)
(At this point 1 year is ~2% of total time in space)
sure - but this time next year is obv more relevant
Christmas also starts earlier every year.
I guess ScienceClock wanted a "first!".
I've been reading such posts for years. Every few months, "Voyager 1 is the most distant man-made object ever!" or "Voyager 1 about to leave the Solar System!"
Well duh!
"is about"
"On November 2026"
I know it's like a nanosecond in astronomical time, but come on...
> Error establishing a database connection
You might need to increase your connection timeout to at least 172800 seconds.
Cannot send email to recipients more than 1 light-day away
The article points that by 2030, we will lose comms with voyager. Is there a way to avoid it?
Trump will turn this into "American spaceships, the best in the world, world class probes, now light years away from Earth to find who knows what treasures lie there."
november 202 6
"Space is big. Really big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean you may think it's a long way down the road to the chemist, but that's just peanuts to space."
This old video is a beautiful and astounding demonstration of just how vastly, hugely, mind-bogglingly big the Universe is, and where in all this endless space our dear favourite little Pale Blue Dot (Earth) resides:
https://m.youtube.com/watch?v=X-3Oq_82XNA
We all Earthlings are extremely lucky to be alive and thriving (or trying to) in such a beautiful bountiful rarest-of-rare ecosystem that somehow survived and thrived despite all the vagaries and vastness of spacetime.
cant wait when Voyager 6 reach earth
V'ger, was looking for a Star Trek reference and HN delivered.
V'ger raises the question of how Starfleet missed it for so long, given how slow the Voyager probes were and how near-future the Star Trek timeline is.
Kind of a dup, but the article linked here is different
https://news.ycombinator.com/item?id=46046260
[dead]
When I read stats like this I realize how stuck in this solar system we are. I wonder if billionaires would care for the planet more if they knew that Earth is honestly just it for humans, for maybe forever.
Nuclear propulsion is the answer to this problem, but we're too busy with internal affairs to get around to trying it.
https://en.wikipedia.org/wiki/Project_Longshot
Carl Sagan's reflection on the Pale Blue Dot( https://en.wikipedia.org/wiki/Pale_Blue_Dot ) image seem relevant:
"From this distant vantage point, the Earth might not seem of any particular interest. But for us, it's different. Consider again that dot. That's here. That's home. That's us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every "superstar", every "supreme leader", every saint and sinner in the history of our species lived there – on a mote of dust suspended in a sunbeam. "
Nah, the whole second-Earth, terraforming nonsense is pure rationalization for whatever they want to do. If they weren’t using that as a post hoc justification, they’d just land on something else.
It gets even better when you think about all the damage we've done in ~200 years of industrial revolution.
We can't keep our perfect home in working order after so little time but they believe we'll transform dead rocks with no atmospheres in paradise...
I’m not aware of any organisation or individual that has actual plans (backed with actual investment) for terraforming anything. This is a straw man argument.
Dork in chief always delivers: https://en.wikipedia.org/wiki/SpaceX_Mars_colonization_progr...
> "We bring you Mars", a rendering of a terraformed Mars at SpaceX Headquarters
You people should stop demonizing billionaires. You're the ones burning the fossil fuels, not them. If their wealth way distributed among more people then those people would spend it damaging the environment which is what people generally do with their money anyway.
They're not going to be alive in 100 years (barring AGI intervention), so why would they care?
This. It's not a spatial problem, it's a temporal one. They are somewhat aware there will be nowhere to run to (I say somewhat because they still spend millions in luxury bunkers), they are just betting that it won't get really bad during their lifetime, maybe their kids lifetime for the more empathetic ones.